Changes in 6.0:
 - Migration from GitHub to NotABug.
 - Additional verbosity level, doTrace=3.
 - `Boruta for those in a hurry` vignette.
 - Extra-trees importance.

Changes in 5.3:
 - Xgboost importance.
 - Codebase modernisation.

Changes in 5.2:
 - New status messages, including proper grammar and a count of
 still undecided attributes. (Thanks to Aristide Mooyaart for
 suggesting this)
 - Boruta to formula conversion functions (getConfirmedFormula,
 getNonRejectedFormula) are back, after a silent disappearance
 in the 2.0 version. (Thanks to Marco Niemann)
 - Documentation fixes.

Changes in 5.1:
 - Documentation fix. (Thanks to Andrew Slack-Smith for spotting
 the problem)
 - ranger VIM providers fixed to support survival problems. (Thanks
 to James Iremonger for spotting this)
 - Various documentation updates.
 - Code and issues on GitHub.

Changes in 5.0:
 - ranger RF implementation replaced randomForest in default
 importance providers, bringing speed and parallel processing
 capabilities. Results should be the same, but there may be minor
 differences. Using getImp=getImpLegacyRfZ restores legacy
 behaviour. See ?getImpLegacyRf for a further discussion.
 - Names of columns in the attStats output changed to reflect the
 fact that Boruta may use arbitrary importance source.
 - Documentation fixes, better organisation of code over files.

Changes in 4.0:
 - Initial rounds were dropped from the algorithm, as they seem
 redundant after implementation of a proper p-value adjustment.
 This should provide noticeable speed-up, however the results
 may be different than in previous versions.
 - TentativeRoughFix interface changes in order to adapt to the
 change mentioned above.
 - Output of the importance source is validated, so that wrong
 values will be clearly reported.
 - Code clean-up.

Changes in 3.1:
 - Better status messages.

Changes in 3.0:
 - More importance adapters defined.
 - Fixed TentativeRoughFix() bug making this function always return
 the original Boruta object without any modification.
 - Built-in multiple-comparisons correction, which breaks
 compatibility with older version of Boruta.
 Use pValue=0.001 and mcAdj=FALSE to trigger the legacy behaviour.
 - Experimental, "forced" mode of Boruta dropped. It is equivalent
 to fixing light argument of Boruta function to TRUE, its
 previously default value.

Changes in 2.1:
 - Fixed attStats() bug making withTentative argument behave
 opposite to what it should do. (Thanks to Jitao David Zhang
 for spotting this)

Changes in 2.0:
  - Allowed to replace randomForest with other importance source.
  - Changes in output; "rand" attributes are now called
  "shadow" ones.
  - ZScoreHistory is now ImpHistory; some scripts and old Boruta
  objects may become incompatible.
  - Documentation updates.
  - Formulae export functions become private.

Changes in 1.5:
  - Improved performance of dealing with huge inputs.
  - Removed redundant decisionHistory from output.

Changes in 1.4:
  - Fixed manual entry suggesting that Boruta can only work
  for classification problems. (Thanks to Allan Engelhardt
  for spotting this)
  - Fixed an error occurring when all attributes are claimed
  Rejected during one of the initial rounds. (Thanks to
  Allan Engelhardt for spotting this)

Changes in 1.3:
  - Fixes to the output. (Thanks to Achim Zeileis for
  suggesting them)

Changes in 1.2:
  - New plotting function plotZHistory.
  - Changes in manual.

Changes in 1.1:
  - Fixed a bug making get*Formula functions throw error
  when Boruta was run with formula provided as a variable.
  - Fixed minor documentation inconsistency.

Changes in 1.0:
  - First public release.

